The present invention relates to a brake apparatus for use in a vehicle.
In a brake apparatus for use in a vehicle such as an automobile, when a great load is imposed on a wheel due to, for example, rapid turning of the vehicle, the disk rotor of the disk brake may be tilted and thereby the brake pad may be pushed back, whereby the pusher of the disk brake such as a piston may move away from the disk rotor, i.e., a so-called knock-back may occur. In addition, when a vehicle is running on a rough road or a rough surface and therefore the wheel and its peripheral components violently vibrate, the brake caliper may be displaced and the brake pad may come to contact the disk rotor, thereby causing a knock-back as mentioned above. Such a knock-back often leads problems. When a knock-back occurs, a pad clearance is increased and thereby responsiveness of the brake apparatus is deteriorated, and in addition to that, irregular contact between the disk rotor and the brake pad easily causes uneven wear of the disk rotor and the brake pad.
With the aim of solving this problem, for example, Japanese Patent Public Disclosure No. 2003-154931 discloses an invention in which an increase of the pad clearance and therefore deterioration of responsiveness of the brake apparatus can be prevented by maintaining the position of the piston in the brake caliper as measures against knock-back.
However, the invention disclosed in the above-mentioned Japanese Patent Public Disclosure No. 2003-154931 still has the following drawback; since the position of the pusher in the brake caliper is maintained against a knock-back, i.e., displacement of the pusher of the disk brake away from the disk rotor, irregular contact of the disk rotor to the brake pad is unavoidably made, whereby uneven wear of the disk rotor and the brake pad may be deteriorated and the brake judder phenomenon may be caused.